Method of shaping the skin planking of vessels



March 18, 1941. v M. a. ANDREKASSEN METHOD OF SHAPING THE SKIN PLANKING OP VBSSELS Fil ed March 21, 19:59

atenied UNITED STATES PATENT OFFICE METHOD OF SHAPING THE SKIN PLANKING OF VESSELS Martin Berg Andreas sen, Arendal, Norway 4 Claims.

The present invention relates to a method and an apparatus for shaping the skin planking of wood vessels. The kind of boats to which the invention is directed are boats of any size in which the skin planking is placed on frames in an abutting relation. Considering one of the planks which constitute such skin or covering, one will easily understand that the shape of the plank and its positioning on the outside of the vessel must 10 be very irregular. Not only must the plank usually be tapering towards one end, but when the plank is clamped-in position onthe framesit is first subjected to a bending and also to a twisting along its longitudinal axis. When thus the planks which together constitute the skin are to be shaped, one must first design the shape of the plank in the plane of the plank. This may take place in a relatively simple manner either by means of moulds adapted for a certain type of boat or by dividing the frames in the boat construction and measuring the width of the plank at the location at which the plank coincides with each frame,

with subsequent drawing ofi the line along which the plank is to be cut. The necessary bending of the plank is produced by placing the plank on the frames and pressing it in position. At the same time the plank will also receive the desired twist according to the angular position of the frames relatively to each other at the location at which the plank is placed on the frames. Through this twisting of the plank, however, the side edges of the plank which are to abut against the side edges of the adjacent plank, will also be subjected to a twisting, and in order to pro 6 duce an exact and tight joint between two adjacent planks, it is therefore necessary to plane such planks in such a manner that their edges along the entire length of same will seat or abut against each other with the whole surface. In brief, each of the planks after being tapered is bent and twisted into the shape that it will occupy in the finished boat and the adjacent edges of the planks are then cut to the desired angles so that these planks when assembled will fit properly along the outside curvature of the boat.

Now taking two planks which are correctly fitted to each other in position on the hull of the boat and letting them straighten themselves out, so that the surface of the plank-becomes plane, r one will understand that the side edge of the plank will have an irregular surface which has a different angle to the plane of the plank at different locations along the length of the plank, according to the twist to which the plank is subiected at the different frames.

In building boats one has previously proceeded in such a manner that each single plank has been manually fitted in position on the boat. This has been a very long and tedious work, which has required great skill of the boat builder. A skilled boat builder has not been able to cover a sail-boat of average size in less than weeks full working time. In mass production of boats one has, however, been able to proceed in a different manner, which has permitted of great economy of work. In such case one has first covered one boat with planks, and subsequently marked the planks and removed them from the frames again and used these planks as moulds for the production of several sets of identical planks for the building of a series of boats of identical shape and size.

It is obvious that the method last described has only small importance for the industry, because it only can be used for a large production, which usually is not the case.

The present invention has for its object to provide a method in which by simple means the individual planks may be planed to a final shape in the work shop, so that the same without further adaptation may be placed in position on the boat. According to the present method this is done in such a manner that a mould is provided on which a certain plank of the skin may be clamped, and which is given such a shape that the plank when clamped on the mold, at each point of its length is given the same relative twisting relatively to the other points of the plank, as

the plank will receive when secured to the frames of the boat on a predetermined location corresponding to the said mould. After the plank in this manner has been shaped with the necessary adaptation in its longitudinal direction and is clamped on to the mold with the necessary twist of the different parts of the plank, one may be means of a. plane which has lateral support against a fixed backing, plane the side edges of the plank in a fixed angle to this backing, whereby the edges of the plank will receive the correct shape with varying angle relatively to the plane of the plank, according to how the plank is clamped at the different points along its length.

According to the invention this method may be carried out in a different way according to the production of a certain boat builder of certain boat types. If a large series of a certain boat type is to be produced, it may for instance be advantageous to produce a large series of moulds as above described, corresponding to all the parts of the surfaces of the boat; but the method according to the invention is not only usuable in connection with the production of large series of boats, but may also with the great advantage be used in the production of a special boat, a mould then being used which consists of a fixed base common for all places of the skin of the boat, and a series of wedge shaped members which correspond to the predetermined points of the frames at which a certain plank is to abut.

Thus by producing a large series of exchangeable wedges with varying angles, one will be able to adapt the mould for the different parts of the skin of the boat, and subsequently in connection with a. constructional drawing of the boat, be able to plane all the planks which "are to cover the outside of the boat, in the work shop without direct adaptation of the planks, when securing the latter on the frames.

In the method according to the invention one may further proceed in a different way, for instance considering the case in which it is desired that each plank shall have one side planed in a right angle to the plane of the plank and the other side planed along the desired twisted line. Or one may consider the case that two corresponding side edges of two planks shall meet with equal area, and in this case one chooses to plane both side edges of the plank in an angle to the plane of the plank, so that the surface areas of the corresponding edges become identical.

The method and the apparatus above indicated and which is the subject matter of the present invention, is to be described in the following with reference to the drawing, which diagrammatically illustrates how the method may be carried out, and the apparatus which it is suggested to use in carrying out the method. One will, however, appreciate that the invention is not limited to such drawing and description which is required to explain the method but only are to be considered as explanatory for the one who wishes to use the invention.

In the drawing:

Fig. 1 is a diagrammatic view of the frames and the streaks in the one-half of a sail-boat.

Fig. 2 is a plan view of a mould for planing one of the planks.

Fig. 3 illustrates a side view of the mould.

Figs. 4, 5, 6, '7 and 8 are sections along the lines IV-IV, V-V, VIVI, VIIVII, VIII-VIlI, respectively in Figs. 2 and 3.

Fig. 9 illustrates the joint between two planks in a method for jointing such planks.

Fig. 10 illustrates the joint in another method of jointing.

In Fig. 1 the frames of the boat are designated s2, s4, s6 and s8. The strokes are designated bl, b2, b3, b4, b5 and the joint lines between two strokeswhich lines in the following will be called seamsare designated 110, nl, n2, n3, n4, 125.

In the drawing the seams are shown as straight lines widest apart on the right side and converging towards the left side. Actually these lines are not usually straight lines, but slightly curved lines. This has, however, little practical importance for the understanding of the invention. In the seams the planks abut against each other, and when in the following a certain edge of a certain plank is to be indicated, this takes place by writing the seam number and the plank number after each other. The lower edge of the plank b2 will thus for instance be called n2, b2, and the upper edge of the plank 3 will in the same manner be called 112, b3. The abutting planks will 75 have an angle to each other the size of which the desired curvature of the hull of the boat is.

produced at the predetermined place.

In Fig. 10 the seam is produced by planing both the plank 1 and the plank 6 in a certain angle to the central axis of the plank, so-that the planks will abut against each .other with the entire planed surface area.

The angle which it is now necessary to give the plank in the seam edge, may be determined from the diagrammatic drawing Fig. 1. Supposing for instance that it is desired to determine the angle for the seam edge at the frame 4 between 11!, b2 and 11!, b3, 9. line is drawn through the intersection between the frame 4 and M, bl and n2, M. Then a line is drawn through the intersection between the frame and 12.2, M and ml, 123. These lines are in the drawing indicated at 8 and 9. Between the lines an angle a is obtained which determines the angle in the seam edge 112 and consequently also determines the angle of M, M and M, M at this point.

A corresponding example is shown for the seam between the planks b4 and b5 in the frame 6. Here an angle a between the lines 8' and 9 is obtained which is far greater than the angle a in the first example. In the case of the seam M and the frame 6 an example is also shown in which the angle a will become negative due to the curvature of the boat in the other direction. It will here be seen that the lines 9" and 8" 'enclose an angle a with each other on the inside of the skin of the boat.

In order to use such angles in the planing of the edges of the plank one must select a reference line which during the planing corresponds to the backing face of the plane against the bench. One may thus for instance select the reference line III in a right angle to the lines 8, 8. 8" without this, however, being conditional for the carrying out of the invention. If it is now desired to plane the edges of the plank in such a manner that a seaming as shown in Fig. 9 is obtained, the plank edges n2, b3, M, 125 and n), bll of the preceding examples are planed in an angle to the reference line equal a, so that the plank edges 112, M, 114, bl, nit, bl0 will be planed in a right angle, as it will appear from Fig. 9. If it is desired that the jointing shall be as shown in Fig. 10, one selects instead of a the half of this angle and plane both the corresponding plank edges in this half angle as it appears from Fig. 10.

For carrying out the method an apparatus as shown in Figs. 2 and 3 and in section in Figs. 4 5, 6, 7 and 8 may be used. This apparatus consists of a bench IS, the plane of which may correspond to the reference line 5 on Fig. 1. On the bench l3 a series of wedge members ll, l5, l6, l1 and I8 is provided, the angle of which is determined according to the measuring of the angle a in the drawing Fig. 1, if it is desired to plane as indicated in Fig. 9, or half of such angle, if it is desired to plane in order to obtain the result which is shown on Fig. 10. Such wedge members are arranged in the longitudinal direction corresponding to the linear distance between the frames 2, l, 6, I etc. A cut plank l 9 is now placed on these wedge members in-such a manner that the edge of the plank which is to be planed, projects beyond the wedges M-ll, but not beyond the working table II. By means of suitable clamps 20, 2|, 2!, 23, 24 the plank I9 is now pressed against the wedges ll-lt so that the plank will receive a twisting at the different points, as it will appear from Figs. 4, 5, 6, 7, 8. For the planing of the'edges a plane 2! is used, the side edge of which is guided against the working table i3, while planing the edges of the plank l9 according to the marking which the plank already has received on the upper surface. In this planing the plank edge will thus be planed in a certain angle. to the surface of the working table along the entire length of the plank; but this angle will vary relatively to the surface of the plank at all places, resulting from the twisting of the plank by means of the diilerent wedges and clamps.

As already mentioned one may proceed in two' diil'erent manners; one may either let the working table with adapted wedge members he formed as permanent moulds corresponding to certainparts of the surface of the boat, or one may use aselection ofwedges it which are secured to the table II for planing of a certain plank.

By means of the method and apparatus according to the present invention, it is possible to cover the boat in the course of one week as compared with previously five weeks. By use of the apparatus according to the invention it is also possible that several workers independently of each other may work with the covering of a boat, one man for instance beginning at the top of the boat and another man at the bottom. In such case, however, it may be possible that some manual fitting is required when the two working forces meet. This is, however. of small importance relatively to the time which is saved by. means of the apparatus according to the invention.

I claim:

1. In the manufacture of vessels such as saillug-boats where a sheathing of wooden planks or boards are mounted edge to edge on ribs forming the skeleton of the boat and where these planks first are shaped to suitable taper according to the varying outside distance from the edge of the boat to its keel at each point along its length, a method for shaping the edge of the planks with such an angle at any point to its plane surface at this point that it when twisted in shape on the said skeleton will abut properly with the meeting edge of the adjacent plank, consisting in the twisting of the plank about its longitudinal axis at each point along its length to the same degree, that each point will be twisted, when twisted and bent in .place on the boat, holding the plank in this twisted position on a working bench, and planing the edge of the plank so held by means of a planing tool, the working edge of which being made to pass along the said edge without changing its angular position with reference to said working bench.

2. Improvement in means for shaping the abutting edges of planks for boats withrespect to the angle of the side edge of the plank to the plane surface of the plank at each point along its length, comprising a working bench with a guiding edge for a planing tool and a plurality of spaced clamping means for the plank, each consisting in means adapted individually to hold the plank at its location at a given angle in relation to the said guiding edge. the said plurality of clamping means being arranged at such a distance from each other so as to correspond to the distance between the ribs in the skeleton of the boat to be built. 7

3. A method according to claim 1, characterized 'by the fact that of two abutting edges one is planed in 90 angle to its plane surface and the other with a varying angle corresponding to this when twisted on to the boat.

4.. A method according to claim 1, characterized by the fact that the two abutting edges of two planks both are planed with varying angle in such a way that they both at each point along their edges will have the same width.

MARTIN BERG ANDREASSEN. 

